Various types of rotary drill bits or rock bits may be used to form a borehole in the earth. Examples of such bits include roller cone bits or rotary cone bits often used in drilling oil and gas wells. A typical roller cone bit comprises a bit body with an upper end adapted for connection to a drill string. A plurality of support arms, typically three in number, depend from the lower portion of the bit body with each arm having a spindle protruding downwardly from said bit body and radially and inwardly with respect to a projected rotational axis of the bit body.
For some applications, modular construction techniques have been used to fabricate drill bits from a bit body and modular support arms. Such modular support arms often included a flat locating face extending in an undeviated or line of sight path to the bit exterior, requiring that the length of the weld bead be perpendicular to a radial line extending from the center of the bit. This section of the weld joint or weld bead perpendicular to a radial line running from the center of the bit is known as the straight section of the weld bead. The profile of the arm approaching the area where the weld was deposited near a pocket formed in the bit body was commonly straight.